public void StylesIntersection_FewStyles_ReturnsDelta()
{
var oldStyles = new Dictionary <Type, IStyle>();
var color = new TextColor(0);
color.FromString("#f00");
oldStyles.Add(color.GetType(), color);
var font = new Font(2);
font.FromString("80% arial");
oldStyles.Add(font.GetType(), font);
var dockAlign = new DockAlign(4);
dockAlign.FromString("top");
oldStyles.Add(dockAlign.GetType(), dockAlign);
var newStyles = new Dictionary <Type, IStyle>();
var whiteSpace = new WhiteSpace(1);
whiteSpace.FromString("nowrap");
newStyles.Add(whiteSpace.GetType(), whiteSpace);
var newFont = new Font(3);
newFont.FromString("5px tahoma");
newStyles.Add(newFont.GetType(), newFont);
var newColor = new TextColor(5);
newColor.FromString("#F00");
newStyles.Add(newColor.GetType(), newColor);
IDictionary <Type, IStyle> actual = _styleSheet.StylesIntersection(oldStyles, newStyles);
Assert.AreEqual(2, actual.Count);
Assert.AreEqual(whiteSpace, actual[typeof(WhiteSpace)]);
Assert.AreEqual(newFont, actual[typeof(Font)]);
}